I've known people who have warm hands even in the most chilling weather and also those having cold hands in a relatively hot climate. Why does this happen?
Though I haven't heard of people having warm hands in cold temperatures (unless your using a hot pack or something), there are biological explanations for cold hands.
Having cold hands even when you're not in a cold environment is common. Often, having cold hands is a part of your body's natural response to regulate your body temperature and shouldn't be cause for concern.
But if you have persistently cold hands, particularly if accompanied by color changes, it could be a warning sign. For example, having cold hands could mean you have a problem with the nerves or blood circulation or a problem with tissue damage in your hands or fingers. If you are outside in extreme cold weather and you have cold hands, you should watch for warning signs of frostbite. - MayoClinic
Other than frostbite, there are also reports of the Reynaud's disease.